Carphone Warehouse has caused me headaches for several months, since I switched to its "paper-free" billing system. Every time I get a notice in my inbox telling me my bill is now available, I click on the website only to be told it has no record of my email address, even though it is the same address used to contact me.

At one stage I received a bill for £145 and was told to pay up or face restrictions on my account. I was due to go away and reluctantly paid to avoid being cut off. I then noticed the phone was connecting to the internet by itself, which would probably account for the high bill and, as if to rub salt in the wound, the Nokia E75 handset developed a screen problem. I tried ringing CPW and visited a branch but failed to get anywhere. CPW told me I couldn't have a new handset because I was two days over the 28-day limit.

My attempts to deal with this sorry tale by email have also failed. JL, south-east London

You really do seem to have experienced the full set of problems and, despite trying to deal with these in a rational and logical way, you have got nowhere. Carphone's meaningless 28-day rule has been applied and it now wants to send off the handset for repair rather than exchange or refund. The issue with online billing is also particularly frustrating because, if you could see the itemised bill, you would be able to work out exactly how you came to owe £145. Carphone Warehouse told Capital Letters that when things go wrong, it wants to "show particular effort to ensure that we are there for customers through thick and thin". Fine words, but in this instance it accepts a failure to live up to expectations and has apologised.

To sort this out, it has exchanged the handset, refunded the incorrect web charges (which came to £31.20), resolved the online billing and given you a line rental discount of £10 per month for the rest of the contract.